Casings used in electronic devices such as portable telephones and smart phones are constructed in general in a flat shape by combining a front casing and a rear casing composed of synthetic resin. In detail, a protection panel for protecting a liquid crystal display window is fixed to the surface of the front casing by fusion bonding or the like. In the prior art, this protection panel has been constructed as a transparent and colorless resin panel. However, with growing demand for fashionable electronic devices, decoration such as fringe decoration fabricated by printing is frequently added as disclosed in Japanese unexamined patent publication No. 2001-318612. In recent years, promising portable telephones comprise a touch panel as a next-generation interface. An example of such a portable telephone provided with a touch panel is disclosed in Japanese unexamined patent publication No. 2000-270063.                Patent Document 1: JP2000-270063(A)        Patent Document 2: JP2001-318612(A)        
Nevertheless, in the prior art described in Japanese unexamined patent publication No. 2001-318612, a liquid crystal display window of an electronic device such as a portable telephone is protected by a protection panel constituting a part of a front casing. Thus, if a touch panel were simply built inside the casing, touch input operation would be blocked by the protection panel, so that the touch panel could not be employed. Thus, in the surface of the front casing, in place of fixing the protection panel which covers the touch input operation surface of the touch panel, a front panel provided with an opening for exposing the touch input operation surface needs to be provided by fusion bonding or the like as disclosed in Japanese unexamined patent publication No. 2000-270063 or the like.
As shown in FIGS. 14 and 15, when such a front panel provided with an opening for exposing a touch input operation surface is used, the periphery of an opening 66 of a front panel 67 covers the outside of the operation region of a touch panel 60. This causes a level difference equal to the thickness of the front panel 67 to occur between a decoration section 70 of the outer surface of the front panel 67 and a touch input operation surface 62. Thus, a pen, a finger, or the like is guided by the level difference edges, and thereby slides frequently on the same portion along the edges of the opening 66 of the front panel 67 of the touch input operation surface 62. This has caused a problem that the touch input function is degraded easily. Further, there has been a problem that when fouling such as fats and oils which have adhered to the touch input operation surface 62 during the input or the like is to be wiped off, the portion near the edges of the opening66 of the front panel 67 is difficult to be wiped completely.
Further, as shown in FIG. 15, the touch panel 60 is fixed to the surface of a display 65 almost directly via an adhesion layer 71. Thus, stress applied from the outside to the touch panel 60 is transmitted directly to the display. This has caused a problem in that the display 65 easily suffers damage.